Plant and animal cells differ in terms of shape, internal arrangements and metabolism. Animal cells have less well-defined shapes than plant cells. The two cell types have different organelles, and the metabolisms of plant cells produce nutrients rather than consume them.
Animal cells vary widely in size and shape. Although the typical animal cell is roughly spherical, many are flattened or irregular in shape. Plant cells are mostly rectangular and tend to form rigid rows of tissue that retain the plant's shape in lieu of a skeleton. This rigidity occurs because plant cells have cellulose walls, which animal cells lack. Instead, animal cells are surrounded with a pliable sheath called a plasma membrane.
Plants and animals share some features within the cells, such as nuclei and various organelles. However, the nucleus of a plant cell is usually offset toward the wall of the cell, whereas animal cells keeps their nuclei near the center of the intracellular fluid. Plant cells have special organelles called chloroplasts, which carry out photosynthesis.
The metabolisms of the cell types also differ. Plants are autotrophic and produce nutrients internally from sunlight. Animal cells require nutrients outside themselves and cannot synthesize proteins without an external food source.